In a capacitive sensor the dielectric gap between the fixed plate and the diaphragm must be strictly maintained if the sensing of the external pressure is to be accurate. Typically the fixed plate may be silicon with signal processing circuits on one side and conductor elements such as solder balls on the other. This fixed silicon plate may be flip chip bonded to a substrate, typically a ceramic material, which contains a diaphragm. External pressure changes on the diaphragm are reflected in changes in the dielectric gap dimension which translates into a change in capacitance. One problem with this construction is that the conductive elements, such a, the solder balls, which contain substantial lead, are susceptible to creep over time and temperature which will change the dimension of the dielectric gap. The stress and strain endured by the capacitive sensor during fabrication and in use can exacerbate this problem and sometimes cause failure of the solder balls resulting in an open circuit. Under filling, a technique used to seal and strengthen integrated circuits, is not applicable because it would fill and rigidify the dielectric gap and diaphragm destroying the fundamental capacitive function and because it uses an organic filler which cannot withstand the high temperatures encountered in fabrication and in some applications of the capacitive sensor, e.g., engine oil, tires. The organic fillers also tend to be more flexible and not suitable for rigidifying a structure.